Method for braking at least one rotating roller of a straightening device, cable processing machine with a straightening device

Description

[0001] The invention relates to a method for braking at least one rotatable roller in a straightening device according to claim 1, and to a cable processing machine with a straightening device according to claim 4.

[0002] As the number of electronic assemblies in industry increases, so do the demands on the quality of cable harnesses and cable connections between the assemblies. Therefore, it is even more important during cable processing to constantly monitor the cable from the insertion stage, through cutting to length, and further processing at the processing stations of the cable processing machines, to prevent damage to the cable.

[0003] The increasing number of cables required also means that cable processing machines must operate ever faster. The output of cable processing machines is a significant economic factor and, along with quality, is a key factor in customers' purchasing decisions.

[0004] Fully automated cable processing machines must be able to perform processing steps such as cutting, stripping, crimping, twisting, and tinning as quickly as possible. Additional processing steps, such as welding cables and automatically winding the processed cables, are available as options. For this purpose, continuous cables are typically drawn into the cable processing machine from a container, such as a cable drum or cable barrel, and straightened by a straightening device. The straightening process relieves tension in the cable, minimizes its inherent twist, and enables axially aligned further processing.

[0005] EP 2 399 856 A1 discloses a straightening device for straightening cables with an upper and a lower row of rollers. These two rows of rollers can be moved relative to each other, with the conveying path of the cable running between the two rows of rollers. The rows of rollers have several rotating rollers for straightening the cable.

[0006] The disadvantage of the known device is that during the final stopping process, the line to be straightened is only braked by friction of the rollers and flexing forces in the line.

[0007] EP 3 290 370 A1 discloses a wire guide device for feeding a wire into a feed device. The wire guide device comprises a braking device with a braking roller and a pressure roller as a pressure element. The braking roller and the pressure roller are arranged opposite one another and are movable relative to one another. The wire is subjected to pressure between the braking roller and the pressure roller and is thereby braked as needed.

[0008] The disadvantage of this known device is that the wire is braked mechanically and a high friction-based heat is generated in the wire, which deforms it during braking.

[0009] DE 10 2013 002 020 A1 discloses a winding device for winding a strand-shaped winding material, comprising a winding drum and a movable traversing arm. An eddy current brake is arranged on the traversing arm as a winding material brake, which, as needed, transmits a braking force to the winding material directed away from the winding drum. By generating the braking force on the winding material, the winding material is pre-tensioned in a downward direction toward the winding material brake.

[0010] The disadvantage of this known device is that the braking force of the winding material brake acts directly on the winding material and in the process the winding material is subjected to a tensile stress, which inevitably deforms the winding material.

[0011] Furthermore, JPS62-248528A discloses a straightening device for straightening a steel wire, which imparts a reverse tensile stress of 5% to 20% of the tensile strength to the steel wire.

[0012] The object of the present invention is to remedy one or more disadvantages of the prior art. In particular, a straightening device is to be created in which damage to the cable to be straightened is prevented due to friction effects during braking of the cables to be straightened, as well as a method for braking at least one rotatable roller in a row of rollers of a straightening device, which brings about gentle braking of the cable to be straightened. Furthermore, a cable processing machine with the straightening device is to be created in which the quality requirements of the cable to be straightened can be maintained high and an interruption of the processing due to a damaged cable during straightening is prevented, as well as an upgrade kit for a cable processing machine is to be created, with which a cable processing machine can be retrofitted.

[0013] This object is achieved by a method for braking at least one rotatable roller of at least one row of rollers in a straightening device according to claim 1 and a cable processing machine comprising a straightening device according to claim 4. Particular embodiments of the invention are defined in the dependent claims. Further developments are set forth in the figures, the description, and in particular in the dependent claims.

[0014] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention with reference to the figures. Lists such as first, second, third, or further serve merely to identify the components.

[0015] The list of reference symbols, as well as the technical content of the patent claims and figures, is part of the disclosure. The figures are described coherently and comprehensively. Identical reference symbols indicate identical components; reference symbols with different indices indicate functionally identical or similar components.

[0016] They show: Fig. 1 a first form of a straightening device (aspect not in the subject matter of the invention) in a perspective view, Fig. 2 the straightening device according to Fig. 1 in a perspective view, with the straightening device shown separately from the braking device, Fig. 3 the straightening device according to Fig. 1 in a side view, wherein the braking device is arranged in an inactive state, Fig. 4 the straightening device according to Fig. 1in a side view, wherein the braking device is arranged in an activated state, Fig. 5 a roller of one of the roller rows of the straightening device in the straightening device according to Fig. 1 in a sectional view, Fig. 6 a cable processing machine with a straightening device according to Fig. 1 in a perspective view, Fig. 7 the straightening device according to Fig. 1 and a further straightening device on the cable processing machine according to Fig. 6 in a perspective view, and Fig. 8 an upgrade kit (aspect not within the subject matter of the invention) for a cable processing machine in a perspective view.

[0017] Fig. 1 to Fig. 5show a straightening device 15 (aspect not within the subject matter of the invention) for straightening an electrical or optical cable 11 in a straightening device 20 along a conveying path 16. The straightening device 20 comprises a straightening device housing 22, on which a first row of rollers 21 with a plurality of rotatably mounted rollers 25 is arranged and on which a second row of rollers 31 with a plurality of rotatably mounted rollers 35 is arranged. In these figures and in the following figures, a roller 25, representing the plurality of rollers 25, and a roller 35, representing the plurality of rollers 35, are provided with the respective reference numerals. The straightening device 20 shown is in a closed state in which the two rows of rollers 21 and 31 are brought closer together and the cable 11 is guided between the rollers 25 and the rollers 35 and rests on the rollers 25 along a conveying direction 17.The rollers 25 are arranged offset from the rollers 35 along the conveying direction 17. The first row of rollers 21 is arranged on a first support 23 and the second row of rollers 31 is arranged on a second support 33. The two supports 23 and 33 are connected to the straightening unit housing 22. The straightening unit 20 comprises a feed drive 27 and a pivot drive 28. The feed drive 27 here comprises a pneumatically controlled drive and feeds the first row of rollers 21 towards the second row of rollers 31 so that the distance between the first row of rollers 21 and the second row of rollers 31 can be reduced until the rollers 35 of the second row of rollers 31 touch the cable 11 and hold the cable 11 or until the cable 11 is clamped between the rollers 25 and the rollers 35.The swivel drive 28 comprises an adjusting spindle 29, which swivels the first row of rollers 21 at an adjustable angle to the second row of rollers 31, so that the cable 11 to be straightened is clamped or held in place in sections in the straightening device 20.

[0018] The straightening device 15 has a magnetic braking device 40 for braking the rotatable rollers 25 of the first row of rollers 21 of the straightening unit 20. The braking device 40 has a magnet holder 45 with a plurality of permanent magnets 41-44, wherein the permanent magnets shown here have a cylindrical structure and are neodymium magnets. The magnet holder 45 is spaced from the rotatable rollers 25 and, in an activated state, is in a contactless braking connection with the rotatable rollers 25 of the first row of rollers 21 of the straightening unit 20. According to the invention, the braking device 40 is designed as an eddy current brake, which acts as an eddy current brake on the rotatable rollers 25 when the line 11 is straightened. The braking device 40 acts in particular on the outer ring 25a of the rotatable rollers 25.

[0019] The braking device 40 has a positioning device 50 for moving the magnet holder 45 and comprises a housing 51 and a guide section 52 arranged on the housing 51. The positioning device 50 has a drive device 55, which pneumatically adjusts the magnet holder 45 relative to the at least one rotatable roller 25 or to the plurality of rotatable rollers 25. In this case, the positioning device 50 moves the magnet holder 45 from a first position in which the magnet holder 45 is in an inactive state (see Fig. 3 ), into a second position in which the magnet holder 45 is in an activated state (see Fig. 4 ). The positioning device 50 is designed to move the magnet holder 45 horizontally, which in this case means essentially normal to the rotational axis 26 of the rotating roller 25.

[0020] The positioning device 50 has a cover plate 57, which is arranged on the housing 51 by means of cylindrical rods 59. The magnet holder 45 has bores that individually accommodate the cylindrical rods 59. The magnet holder 45 is mounted on the cylindrical pins 59 so that it can move toward the cover plate 57. Preload springs 58 are arranged on the cylindrical pins 59 and preload the magnet holder 45 relative to the housing 51, thus preventing the magnet holder 45 from tilting when the magnet holder 45 is moved from a first position to a second position.

[0021] The braking device 40 is connected to a control device 80 for controlling the braking device 40. The control device 80 is connected to the positioning device 50 via control lines 81 and is configured to transfer the magnet holder 45 from a first position, in which the braking device 40 or the magnet holder 45 is in an inactive state, to at least a second position, in which the magnet holder 45 is in an activated state. This allows a contactless braking connection to be established from the permanent magnets 41-44 to the rotatable rollers 25 when straightening the line 11. The contactless braking connection acts primarily on the outer ring 25a of the rotatable rollers 25.

[0022] Fig. 5shows the rotatable roller 25, which is arranged on the row of rollers 21 of the straightening device 20. The rotatable roller 25 has an inner ring 25b and an outer ring 25a. A row of balls is arranged as a rolling element unit 25c between the inner ring 25b and the outer ring 25a. The inner ring 25b serves to fasten the row of balls on the axis 30 of the row of rollers 21 of the straightening device 20, with the inner ring 25b being arranged firmly on this axis 30. The rotatable outer ring 25a is arranged on this axis 30 with the aid of the rolling element unit 25c so as to be rotatable about the axis of rotation 26 and rotates according to the cable feed speed. The rotatable outer ring 25a has a groove 32 for centrally guiding the cable 11 to be straightened. The rollers 35, which are arranged on the roller row 31 by means of an axis, are constructed identically to the rollers 25.

[0023] In an alternative embodiment, the rollers are each fixedly mounted on rotating axles on the roller row. The axles rotate with the rollers around the rotation axis, allowing the cables to be straightened in the straightening unit (not shown).

[0024] Another embodiment of the inventive magnetic braking device (not shown here) features an electromagnet instead of the previously described permanent magnets. The magnetic field strength can be varied using the control device to adjust the magnetic braking effect.

[0025] The method for braking the rotatable roller 25 in the straightening device 15 is described below with reference to Fig. 1 , Fig. 3 and Fig. 4 described.

[0026] First, the cable 11 to be straightened is unwound from a bundle, manually drawn into the straightening device 15, and placed onto the straightening rollers 25 of the first row of rollers 21. The straightening device 20 is initially in an open state so that the two rows of rollers 21 and 31 are sufficiently spaced apart. In a further step, the straightening device 20 is advanced using the feed drive 27 so that the rollers 35 of the second row of rollers 31 subsequently rest on the cable 11. Furthermore, the second row of rollers 31 is pivoted using the pivot drive 28 and pressed onto the cable 11. The cable 11 is then straightened, with the cable 11 being pulled through the straightening device 15. The cable is pulled in by a power-driven cable pull-in device, which is arranged at a distance from the straightening device 15 in the conveying direction (see Fig. 7). The rollers 25 of the first roller row 21 and the rollers 35 of the second roller row 31 are set in rotation. For braking, the magnet holder 45 of the braking device 40 is moved from a first position in which the magnet holder 45 of the braking device 40 is in an inactive state (see Fig. 3 ), into a second position in which the magnet holder 45 of the braking device 40 is in an activated state (see Fig. 4). In the inactive state, the magnet holder 45 is located in the immediate vicinity of the end plate 57, with the preload springs 58 in the compressed state. In the activated state, the magnet holder 45 is located directly below the rotating rollers 25, with the preload springs 58 in a relaxed state. In a further step, the effective braking of the rotating outer rings 25a of the rollers 25 of the first roller row 21 takes place with the permanent magnets arranged on the magnet holder 45, wherein the braking device according to the invention acts on the rotating outer rings 25a of the rollers 25 according to the principle of the eddy current brake, without touching them. The braking device 40 is thus in a braking connection with the rotating outer rings 25a of the rollers 25.

[0027] In an alternative embodiment, the rotating rollers are each arranged on a rotating axle on the row of rollers on the straightening unit and are rigidly connected to this rotating axle. The rotating axle rotates with the roller arranged thereon about a rotational axis, with this rotational axis extending along the longitudinal extent of the rotating axle. The contactless braking effect acts on the rotating rollers of the respective roller row (not shown).

[0028] Fig. 6shows a cable processing machine 70 with a straightening unit 73 and with a straightening device 15 as described above. As described here, the cable processing machine 70 can have various processing steps, such as straightening, cutting to length, stripping, crimping, twisting, and tinning. A container 75 containing a cable 11 in the form of an endless cable is arranged in front of the straightening device 15. The cable 11 is drawn into the cable processing machine 70 and straightened in the straightening device 15. To draw the cable 11 through the straightening device 15, a cable drawing device 90 is used, as described below, which is arranged downstream of the straightening device 15 in the conveying direction. Fig. 7shows the straightening unit 73 with two straightening devices 15 and 15a arranged side by side, each having two straightening units 20a-20d. One of these straightening devices 15, 15a has a braking device 40, as described here, for braking the rotatable rollers in one of the rows of rollers of the straightening unit 20a. The cable processing machine 70 has a control device 80, as described here, for controlling the braking device 40 of the straightening device 15. In addition, the control device 80 is electrically connected to the feed drive, the pivot drive of the straightening units 20a and 20c, and to a cable pull-in device 90 by means of the control lines 81. The cable pull-in device 90 of the cable processing machine 70 pulls the cable 11 in the conveying direction 17 through the straightening units 20a and 20c.The control device 80 has a processor 85 which processes control commands and transmits them to the drive device 27, 28 and 55, to the cable pulling device 90 and to the braking device 40 and / or the straightening devices 20a and 20c. The control commands are transmitted according to a predefined sequence of steps to the drive devices 55, to the cable pulling device 90 and to the braking device 40 and to the drive devices 27, 28 of the straightening devices 20a and 20c. The two straightening devices 20a and 20c are arranged offset by 90° to one another. In an embodiment of the straightening unit (not shown), each of the devices shown in . Fig. 7 The straightening units 20a-20d shown have a braking device as described here.

[0029] Fig. 8shows an upgrade kit 100 (aspect not within the subject matter of the invention) for a cable processing machine, which comprises a braking device 40 as described here for braking at least one of the rotatable rollers in a row of rollers of a straightening device, in particular for braking several rotatable rollers in a row of rollers of a straightening device. The upgrade kit 100 has a control device 80 with a processor 85, which is connected to the drive device 55 of the positioning device 50 for controlling the braking device 40. List of reference symbols

[0030] 11Line 15Straightening device 15aStraightening device 16Conveyor path 17Conveyor direction 20Straightening device 20a-20dStraightening devices 21First row of rollers 22Straightening device housing 23First carrier 25Rollers of 21 25aOuter ring of 25 25bInner ring of 25 25cRolling element unit of 25 26Rotary axes of 25 27Feed drive 28Pivot drive 29Adjusting spindle 30Axle of 25 31Second row of rollers 33Second carrier 32Groove of 25a 35Rollers of 31 40Braking device 41-44Permanent magnets 45Magnet holder 50Positioning device 51Housing of 50 52Guide section 55Drive device 57End plate 58Pre-tension springs 59Cylinder rods 70Cable processing machine 73Straightening unit 75Container 80Control device 81Control cables 85Processor 90Cable pull-in device 100Upgrade Kit

Claims

1. A method for braking at least one rotatable roller (25, 35) from at least one roller series (21, 31) in a straightening device (15; 15a) for straightening a cable (11) being drawn through the straightening device along a conveying path (16) by an external cable pull-in device (90), in particular an electrical or optical cable, comprising a straightener (20; 20a-20d), with a first roller series (21) and with a second roller series (31), which can be moved relative to each other and between which the conveying path of the cable runs, wherein at least one of the two roller series (21, 31) has several rotatable rollers (25, 35), wherein the straightening device further comprises a braking device (40) for braking at least one of the rotatable rollers (25, 35) from at least one of the two roller series (21, 31) of the straightener (20; 20a-20d), in particular for braking several rotatable rollers (25, 35) from at least one of the two roller series (21, 31) of the straightener (20; 20a-20d), wherein the braking device (40) is a magnetic braking device in the form of an eddy current brake, comprising at least one permanent magnet or at least one electromagnet, which is configured in such a way that the braking effect is initiated by the rotatable rollers (25, 35) as a function of their rotational speed caused by the drawn cable, wherein the method comprises the following steps: - Straightening the at least one cable (11), and - Braking at least one of the rotatable rollers (25, 35) from at least one roller series (21, 31) in the straightening device (15; 15a) with the braking device (40), wherein the braking effect can be adjusted without contact, and adjusted to a pull-in speed of the cable, and wherein the braking effect is initiated by the rotatable rollers (25, 35) as a function of their rotational speed caused by the drawn cable.

2. The method according to claim 1, characterized in that the braking device (40) is transferred from a first position, in which the braking device (40) is in an inactive state, at least sectionally into a second position, in which the braking device (40) is in an activated state.

3. The method according to claim 1 or 2, characterized in that the braking device (40) has a contactless braking effect on the at least one rotatable roller (25, 35) of the roller series (21, 31) of the straightening device (15; 15a).

4. A cable processing machine (70) comprising a straightening device (15; 15a) for straightening a cable (11) being drawn through the straightening device along a conveying path (16) by an external cable pull-in device (90), in particular an electrical or optical cable, comprising a straightener (20; 20a-20d) with a first roller series (21) and with a second roller series (31), which can be moved relative to each other and between which the conveying path of the cable runs, wherein at least one of the two roller series (21, 31) has several rotatable rollers (25, 35), the straightening device further comprises a braking device (40) for braking at least one of the rotatable rollers (25, 35) from at least one of the two roller series (21, 31) of the straightener (20; 20a-20d), in particular for braking several rotatable rollers (25, 35) from at least one of the two roller series (21, 31) of the straightener (20; 20a-20d), wherein the braking device (40) is a magnetic braking device in the form of an eddy current brake, comprising at least one permanent magnet or at least one electromagnet, which is configured in such a way that the braking effect is initiated by the rotatable rollers (25, 35) as a function of their rotational speed caused by the drawn cable, wherein the straightening device (15; 15a) is arranged in particular directly after a container (75), and a control device (80) for controlling the braking device (40) is advantageously further present, and in particular this control device (80) is also designed to control the straightener (20; 20a-20d).

5. The cable processing machine (70) according to claim 4, characterized in that the straightening device (15; 15a) comprises an additional straightener (20c, 20d), wherein the two straighteners are arranged offset by 90° relative to each other, and the braking device (40) is preferably arranged on the first straightener (20a) in the conveying direction.